U.S. patent number 4,446,602 [Application Number 06/296,486] was granted by the patent office on 1984-05-08 for machine operator protection system.
This patent grant is currently assigned to Trutzschler GmbH & Co. KG. Invention is credited to Fritz P. Hosel, Hans-Jurgen Marx.
United States Patent |
4,446,602 |
Marx , et al. |
May 8, 1984 |
Machine operator protection system
Abstract
A system for monitoring and securing a zone associated with a
power driven textile machine, which machine includes a part which
moves when the machine is in operation in a manner to endanger an
individual present in the zone, which system includes a radiation
emitting device for producing a beam of directed radiation and for
directing such beam along a path coincident with at least one
boundary of the zone, a radiation responsive device positioned in
the path of the radiation beam for producing an output indication
when it is not receiving the directed radiation and a control unit
connected to the radiation responsive device for halting movement
of the part in response to appearance of the output indication.
Inventors: |
Marx; Hans-Jurgen
(Monchengladbach, DE), Hosel; Fritz P.
(Monchengladbach, DE) |
Assignee: |
Trutzschler GmbH & Co. KG
(Monchengladbach, DE)
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Family
ID: |
6110683 |
Appl.
No.: |
06/296,486 |
Filed: |
August 26, 1981 |
Foreign Application Priority Data
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Aug 29, 1980 [DE] |
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3032584 |
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Current U.S.
Class: |
19/.21; 19/80R;
19/81; 250/221 |
Current CPC
Class: |
D01G
31/00 (20130101); D01G 7/06 (20130101) |
Current International
Class: |
D01G
7/00 (20060101); D01G 31/00 (20060101); D01G
7/06 (20060101); D01G 031/00 (); D01G 007/12 () |
Field of
Search: |
;19/.21,8R,81
;250/221 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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2944588 |
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May 1981 |
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DE |
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3032584 |
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Jun 1982 |
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DE |
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1262031 |
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Feb 1972 |
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GB |
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1342144 |
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Dec 1973 |
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GB |
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1363468 |
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Aug 1974 |
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GB |
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1448987 |
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Sep 1976 |
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GB |
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1457582 |
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Dec 1976 |
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GB |
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1462235 |
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Jan 1977 |
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GB |
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1539570 |
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Jan 1979 |
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GB |
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2060113 |
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Apr 1981 |
|
GB |
|
Other References
Kurt Trulley, "Beispiele zur Sicherung von Gefahrenstellen an
Textilmaschinen", Spinner Weber Textilveredlung, No. 9, 1962, pp.
851-855..
|
Primary Examiner: Rimrodt; Louis
Attorney, Agent or Firm: Spencer & Frank
Claims
What is claimed is:
1. A system for monitoring and securing a selected one of a
plurality of danger zones associated with a power driven machine
for opening textile fiber bales, which machine includes a removal
member mounted for displacement between two operating positions
each associated with a respective danger zone, the removal member
being driven, when it is in a selected operating position and the
machine is in operation, to move in a manner to endanger an
individual present in the respective zone associated with that
position, said system comprising: radiation emitting means
associated with each danger zone for producing at least one beam of
directed radiation which is directed along a substantially closed
path which completely encloses its associated danger zone;
radiation responsive means positioned in the path of the radiation
beam associated with each danger zone for producing an output
indication when the at least one beam is interrupted at any point
along the substantially closed path; control means connected to
said radiation responsive means for halting movement of the removal
member in response to appearance of such output indication; and
signal generator means responsive to displacement of the removal
member between its operating positions for actuating only that one
of said radiation emitting means and its associated radiation
responsive means whose beam path encloses that zone associated with
the existing operating position of the removal member.
2. An arrangement as defined in claim 1 wherein the removal member
is displaceable by rotation through an angle of 180.degree. between
its two operating positions.
3. An arrangement as defined in claims 1 or 2, wherein said signal
generators are constituted by pushbutton switches.
4. An arrangement as defined in claim 1 wherein the machine
includes a support for the removal member, which support is
provided with a horizontal passage through which the beam path
extends.
5. A system as defined in claim 1 wherein said control means
comprise a monitoring device connected to monitor the output of
said radiation responsive means and to produce an output signal in
response to production of an output indication by said radiation
responsive means, and a safety switch connected to said monitoring
device for halting movement of the removal member in response to
production of an output signal by said monitoring device.
6. A system as defined in claim 5 further comprising testing means
operatively associated with said radiation emitting means, said
radiation responsive means and said safety switch for permitting
the operation of said radiation emitting means and said radiation
responsive means to be tested while preventing movement of the
removal member.
7. A system as defined in claim 6 wherein said testing means
comprise a reset switch movable between a first position in which
it permits said radition emitting means and said radiation
responsive means to be placed into operation while preventing
movement of the removal member, and a second position in which it
permits movement of said removal member while permitting said
radiation emitting means and said radiation responsive means to
remain in operation.
8. An arrangement as defined in claim 1 wherein said radiation
emitting means associated with each zone produce at least two beams
constituting respective parts of the associated substantially
closed path, and said radiation responsive means associated with
each zone comprise at least two radiation receivers, each disposed
for receiving a respective beam of the associated closed path.
9. An arrangement as defined in claim 8 wherein said radiation
emitting means and said radiation responsive means are arranged for
causing at least one of the two beams associated with each zone to
be common to both danger zones.
10. An arrangement as defined in claim 1 wherein said radiation
emitting means and said radiation responsive means are arranged for
causing the closed path associated with one danger zone to differ
spatially at least in part from the closed path associated with the
other danger zone.
Description
BACKGROUND OF THE INVENTION
The present invention relates to an apparatus for monitoring and
securing accessible danger areas at power driven textile machines,
particularly bale openers for textile fiber bales emloying movable
fiber removal members.
In order to prevent accidents at power driven textile machines,
particularly those incorporating movable elements, a known measure
involves the provision of a main power switch. Actuation of the
main power switch by a person immediately interrupts the power
supply to the drive of the machine, i.e. the drive for the machine
is cut off. However, since the main power switch is disposed on the
movable element itself, the danger of accidents during
manipulations at the machine is not completely eliminated.
SUMMARY OF THE INVENTION
It is an object of the present invention to interrupt a machine
movement which is endangering an individual even without contact by
a person.
The above and other objects are achieved, according to the
invention, by a system for monitoring and securing a zone
associated with a power driven textile machine, said machine
including a part which moves when the machine is in operation in a
manner to endanger an individual present in the zone, which system
includes radiation emitting means for producing a beam of directed
radiation and for directing such beam along a path coincident with
at least one boundary of the zone, radiation responsive means
positioned in the path of the radiation beam for producing an
output indication when it is not receiving the directed radiation,
and control means connected to the radiation responsive means for
halting movement of the part in response to appearance of the
output indication.
With such a monitoring and safety arrangement, no physical contact
with the moving element of the machine is necessary to switch off
the machine, or the moving part, since the drive therefor is
already switched off if a person comes too close to the machine or
the part. Advisably, photoelectric barriers are used for this
purpose. However, other, preferably highly directional, radiation
emitters and receivers can also be employed, e.g. lasers, infrared
light, ultrasound or the like.
Preferably, when the moving element, such as a removal member in
the case of a bale opener, is in the operating position, the
associated danger zone is secured by a safety device, e.g. a
photoelectric barrier, and whenever the moving element turns into
another operating position, a signal generator switches from one
safety device, e.g. for one danger zone, to another safety device,
e.g. for a different danger zone.
In this way it is possible to automatically secure the danger areas
of the machine which may change in the course of the working
process, so that only the area which currently presents a danger is
being monitored while the remaining area remains freely accessible.
While work proceeds in the danger area, new fiber bales can be set
up in the remaining area.
Advisably the switching occurs after a complete rotation of the
removal member of a bale opener through about 180.degree.. The
safety device and with it the drive are switched on only if the
removal member is in the precise operating position. In this way it
is assured that removal of fiber from fiber bales occurs in a
straight line. If the working member has reached its operating
position, a switch must be actuated which emits a signal for both
the safety device and for the drive.
Preferably the signal generator for the safety device is a push
button which is actuated by the removal member. According to a
particularly preferred embodiment, the holding device for the
removal member has a horizontal opening, when seen in the operating
direction, i.e. a passage for the beams of the photoelectric
barrier or the like. In this way, one photoelectric barrier, i.e.
the photoelectric barrier associated with the removal member when
it is in the operating position, is used simultaneously for two
different safety devices. This arrangement is of advantage if very
large danger zones are to be secured for which the beam power of a
single photoelectric barrier is not sufficient.
Embodiments of the invention have the form of an apparatus for
monitoring and securing accessible danger areas around power driven
textile machines, particularly bale openers for textile machines
having movable removal members, and includes a transmitter and a
receiver between which a beam passes, an interruption of the beam
path between the transmitter and the receiver actuating a signal
which is used to directly interrupt the dangerous movement of the
power driven operating means, and the holding device for the
removal member is provided with a horizontal opening, when seen in
the operating direction, for the passage of the beam.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a simplified pictorial plan view of an embodiment of
apparatus according to the invention with two photoelectric
barriers each in a first position.
FIG. 2 is a partly schematic, partly pictorial view of a switching
device with push buttons usable in the apparatus of FIG. 1.
FIG. 3 is a plan view similar to that of FIG. 1 of an embodiment of
an apparatus employing three photoelectric barriers in a second
position.
FIG. 4 is a simplified pictorial elevational view of the apparatus
of FIG. 3.
FIG. 5 is a block circuit diagram for an embodiment of a signal
processing circuit for a safety system according to the
invention.
FIG. 6 is a block circuit diagram of a specific form of
construction of the circuit of FIG. 5.
FIGS. 7, 7a, 8 and 9 are circuit diagrams of suitable embodiments
of components of the circuit of FIG. 6.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows a bale opener presenting two danger zones I and II
which are secure by means of two photoelectric barriers each
composed of a light beam emitter 10 or 20, deflecting mirrors 11,
12 and 13 or 21, 22 and 23, and a light receiver, e.g. a
photoelectric sensor, 14 or 24.
To secure danger zone I, emitter 10 sends a light beam which is
deflected in successsion by mirrors 11, 12 and 13 to the receiver
14. The beam path of the photoelectric barrier 10 to 14 in this way
forms a rectangular perimeter which completely encloses, within
danger zone I, a row of fiber bales 1 and a movable removal member
2 as well as part of the movable support device 3 carrying member
2. The beam path from transmitter 10 to receiver 14 is shown by
arrows. The removal member 2 and the holding device 3 are mounted
to move along rails 4 in the direction shown by a double arrow
associated with device 2.
On the other side of the holding device 3, the second photoelectric
barrier 20 to 24 is provided for enclosing the danger zone II, this
barrier including the transmitter 20, the deflecting mirrors 21,
22, and 23 and the receiver 24. While the photoelectric barrier 10
to 14 for the danger zone I is in operation, the photoelectric
barrier 20 to 24 for danger zone II is deactivated.
If the light beam of the actuated barrier is interrupted, all
movement of the removal member 2 and of the holding device 3 is
braked and stopped. The holding member 3 can be rotated about a
vertical axis through an angle of 180.degree., as indicated by the
circular double arrow, so that the removal member 2 is placed above
the row of fiber bales 1a in danger zone II.
The protective system according to the invention, as depicted in
FIG. 1, may be provided with a barrier actuating system such as
that shown in FIG. 2 where the holding device 3 is provided with
two lateral projections 31 and 32 each of which can close a
respective push button switch 5 or 6 when rotated into either one
of two angular positions spaced 180.degree. apart. The push button
switches 5 and 6 are part of a circuit which includes the
transmitters 10 and 20 and a voltage source 7. By closing one push
button switch 5 or 6, the respective associated transmitter 10 or
20 is put into operation. In this way switching is effected from
photoelectric barrier 10-14 for danger zone I to photoelectric
barrier 20-24 for danger zone II, and vice versa.
FIG. 3 shows a second embodiment of the invention in which each
photoelectric barrier 10-14 and 20-24 forms three sides of a
rectangle with the remaining side being located in the area of the
holding device 3. In this area a third photoelectric barrier
including a transmitter 40 and receiver 41 is arranged to extend in
the direction of travel of the holding device 3. This photoelectric
barrier 40, 41 is always actuated, i.e. also while switching
between photoelectric barriers 10-14 and 20-24 is taking place. The
transmitter 40 sends a beam through a horizontal passage 33
disposed in the middle of the lower region of the holding device 3
when seen in the operating direction, parallel to tracks 4, as
shown in FIG. 4.
In the signal processing circuit of FIG. 5, the signal generator
50, which may be push button switch 5, emits a signal when the
machine 2, 3 is positioned to operate in danger zone I while the
signal generator 51, which may similarly be push button switch 6,
emits a signal when the machine 2, 3 is positioned to operate in
danger zone II. The signal from either generator is received in a
photoelectric barrier monitor control 52 which is associated with
the corresponding photoelectric barriers 10-14, 20-24, and 40, 41
of the safety system. A reset device 54 is also associated with the
control for resetting the system after it has been actuated.
The photoelectric barrier 40, 41 is always in operation. If neither
of the two signal generators 50, 51 is emitting radiation, the
machine 2, 3 cannot be switched on, or is switched off. In this
way, the correct operating positions of the removal members 2 and
of the holding device 3 are monitored simultaneously.
The specific circuit of FIG. 6 performs the further function of
permitting testing of the safety system. In the circuit of FIG. 6
the barrier control monitor 52 includes a selector circuit 53 to
which the signal generators 50 and 51 are connected to provide a
signal identifying the present operating position of machine 2, 3,
and particularly of device 3. Selector circuit 53 is electrically
connected to three monitoring devices 57, 58 and 59, each
associated with a respective one of the barriers 10-14, 20-24 and
40, 41, as well as to a safety switch 55 and a testing device
56.
Safety switch 55 is connected in the power supply circuit of a
motor 34 which is the drive motor for holding device 3. Testing
device 56 is actuatable by a reset device 54 which may be a switch
which must be unlocked by a special key before it can be
operated.
In the operation of the circuit of FIG. 6, movement of device 3
into one of its operating positions actuates one of the signal
generators 50 or 51 to produce a signal which causes the selector
circuit 53 to in turn actuate a selected one of light barriers
10-14 and 20-24 and barrier 40-41. Selector circuit 53 can do this,
for example, by activating all three transmitters 10, 20 and 40 via
testing device 56 and by activating the monitoring devices 57 or 58
and 59 associated with the selected barriers. Switch 55 can be
connected to initially be closed upon actuation of a signal
generator and subsequently opened upon production of an output
signal by any monitoring device when that device is activated and
the light beam transmission path between its associated transmitter
and receiver has been interrupted.
At the start of operation, the selected barriers can be checked by
operating reset device 54 to cause testing device 56 to initiate a
simulated malfunction, as by interrupting the supply of operating
power to all transmitters. If the result is positive, power is
again supplied to the transmitters and reset device 54 is switched
to a normal operating position. Preferably, the circuit components
are interconnected so that switch 55 does not close until device 54
has been switched to this normal operating position.
If during operation of the machine, a light beam is interrupted,
all movement of the operating member 2 and of the holding device 3
is stopped, and restarting is possible only by operating the reset
device 54. The reset device 54 is advisably so located that the
operator must first step entirely away from the danger zone I or
II, respectively, of the machine 2, 3 before the machine can be
switched on again, i.e. the operator must check out the danger zone
I or II. The spatial arrangement is advisably such that the reset
device is at the end of the machine opposite the operator's penal.
The entire control system is preferably constructed using relays in
such a manner that if there is a drop in voltage or a defect, the
machine 2, 3 is always switched off.
One suitable embodiment of elements 54, 55 and 56 of the circuit of
FIG. 6 is shown in FIGS. 7, 7a, 8 and 9. FIG. 7 illustrates the
circuitry of a portion of testing device 56, together with reset
device 54, which has the form of a simple pushbutton switch that is
normally open. FIG. 7a shows a second portion of testing device 56,
this being the portion connected to control the actuation of a
respective light beam transmitter, for example transmitter 10. FIG.
8 illustrates an embodiment of safety switch 55 connected to
control the supply of operating power to motor 34. Finally, FIG. 9
shows one of the monitoring devices, specifically monitoring device
57 connected to monitor the output signal from receiver 14. Not
shown are the connections from selector circuit 53, which
additionally control the light barrier selection and enablement of
safety switch 55 in response to actuation of a respective one of
the generators 50 and 51.
FIGS. 7 and 9 illustrate relay coils E, F, G and I, and their
associated contacts, all of which bear the same reference character
and are shown in their normal position, that is the position when
their associated relay coil is deenergized. The terminals of the
circuit portion shown in FIG. 7a are connected in circuit with an
associated light beam transmitter, for example transmitter 10,and
actuate the associated transmitter when a short circuit appears
across those terminals. Similarly, the terminals of the circuit
shown in FIG. 8 are connected in series with motor 34 so that the
motor will be supplied with operating power only when a short
circuit appears across those terminals. Finally, the terminals of
the circuit of FIG. 9 are connected across the output of an
associated light beam receiver 14 so that a voltage appears across
those terminals when a light beam is impinging on the associated
receiver.
At the start of operation, reset switch 54 is closed, and held in
the closed position, so that an energizing voltage is applied via
normally closed contacts F.sub.4 and G.sub.4 across relay coils E
and I. This closes relay contacts I.sub.1, E.sub.2, I.sub.4 and
E.sub.4, and opens contacts I.sub.5 and E.sub.5. As a result, a
current path for maintaining relay coils E and I energized is
established, light beam transmitter 10 is turned on and the output
of receiver 14 is connected across relay coils F and G, thereby
energizing the latter if receiver 14 is receiving a light beam.
Energization of relay coils F and G opens contact F.sub.4 and
G.sub.4, while closing contacts F.sub.1 and G.sub.1 to provide a
second connection path to relay coils F and G, closing contacts
F.sub.2 and G.sub.2 to provide a second current path for
maintaining transmitter 10 energized, and closing contact F.sub.5
and G.sub.5. Since coils E and I are still energized, contacts
E.sub.5 and I.sub.5 remain open, so that no power can yet be
supplied to motor 34. In this operating state, light barrier 10-14
can be broken for testing purposes. This will cause relay coils F
and G to be deenergized, and this can be observed in any suitable
manner. When the light barrier is restored, relay coils F and G
will be reenergized, via contact I.sub.1, and all of the F and G
contacts will therefore again be returned to their positions
associated with energization of their respective relay coils.
After testing has been completed, reset button 54 is opened,
whereupon relay coils E and I are deenergized while coils F and G
remain energized to maintain transmitter 10 and the monitoring
device associated with receiver 14 active and to supply operating
power to motor 34. If, during subsequent operation of the system,
the light beam to receiver 14 should be blocked, i.e. the light
barrier should be broken, relay coils F and G will be deenergized,
as a result of which transmitter 10 will be deactivated and motor
34 will be halted.
It will be understood that the above description of the present
invention is susceptible to various modifications, changes and
adaptations, and the same are intended to be comprehended within
the meaning and range of equivalents of the appended claims.
* * * * *